Citizen scientists participating in the ‘Invasion of the Oriental Hornet in Andalusia’ project have defined a map with the expansion zones of this invasive species, which has increased by up to 30% between 2023 and 2024, with the provinces of Cadiz, Malaga, and Seville being the most affected. This study aims to track the distribution of this species (‘Vespa orientalis’) and predict its impact on ecosystems and the local economy.
The results of the initiative, led by citizen scientists from the Environmental Education Association ‘El Bosque Animado’ (Malaga), demonstrate that the 30% increase experienced by this invasive species between 2023 and 2024 implies a growing risk to native biodiversity, as well as to sensitive economic sectors such as agriculture and beekeeping, due to predation on honeybees and even other local wasps. «It also poses a risk to coexistence with humans, and its presence as a pest can affect specific crops like grapes. However, it cannot be combated with pesticides because this method could affect local biodiversity; the only way to mitigate it is nest removal,» explains the biologist from ‘El Bosque Animado’ and scientific advisor to the project, Florent Prunier.
The project’s scientific goals included detecting the species, monitoring its colonized areas, updating distribution maps, identifying prey species, facilitating the prediction of its area of influence, and assessing the utility of applications for monitoring invasive species in citizen science.
Citizen Participation
To create the map, citizen scientists used the Observation.org platform during the summer and fall of 2024. Through a mobile application, they documented and recorded the presence of the Oriental hornet, which was initially concentrated in Cadiz and Malaga but later observed in all Andalusian provinces.
The study is supported by the Citizen Science Office of Andalusia, coordinated by the Descubre Foundation – Ministry of University, Research, and Innovation and the Pablo de Olavide University, aiming to promote the use of this methodology among different stakeholders in the region. Specifically, it involves the active involvement of a community to address a local problem through knowledge-based actions.
As project coordinator Florent Prunier explains, the Oriental hornet originates from regions in South Asia, the Middle East, and North Africa and has spread to Europe, adapting to the Mediterranean climate. «The rapid spread of ‘Vespa orientalis’ underscores the need to establish early monitoring systems, control protocols, and citizen awareness campaigns to mitigate its impact on the environment and the Andalusian economy,» he adds.
Members of the Environmental Education Association ‘El Bosque Animado’.
This expert leads the project in collaboration with researcher Diego Gil-Tapetado, postdoctoral researcher at the University of Murcia, platform coordinator Observation.org in Spain, Julio Rabdán, and predoctoral researcher at the Doñana Biological Station, Jairo Robla.
A Varied Diet
Regarding its varied diet, the research team specifies that the Oriental hornet consumes animal remains such as birds, often sparrows and pigeons, small mammals like rats, reptiles such as lizards and snakes, freshwater and marine fish, and invertebrates, including large grasshoppers, beetles, aphids (or their honeydew), and even sea urchins, jellyfish, and shrimp.
Its diet is not limited to animals. The Oriental hornet also feeds on feces and human food leftovers, tree sap like tamarisk and vineyards, where it feeds on ripe grapes, as well as ivy fruits. It also consumes late-season flowering plant species like fennel, sage, wild olive, and viper’s bugloss, as well as exotic ornamental plants native to its original area, such as shrubs from the myrtle family or agave.
Exponential Growth
Citizen scientists have documented and recorded the presence of the Oriental hornet through a mobile application, with the option to attach photos to validate observations. Using this resource, which includes geolocation, participants have placed this species on an interactive map that enhances data visualization and understanding.
The expert team relied on a data history collected since 2018, revealing that the presence of the hornet was initially concentrated in Cadiz province and has been growing exponentially year after year. To disseminate the study results, project coordinators have organized a series of outreach events such as ‘Cafés with Science’ and an informative workshop, and have participated in events in the Ronda mountain range, such as the ornithological fair in Montejaque and the agro-artisans market in Genalguacil.
Citizen Science for Biodiversity Studies
The project is co-financed by the Ministry of University, Research, and Innovation, responsible for research and innovation policies in Andalusia, the Spanish Foundation for Science and Technology, the Ibercivis Foundation – pioneers of Citizen Science Observatory in Spain, the Institute of Academies of Andalusia, the Ministry of Educational Development and Professional Training, the Andalusian Society for Science Communication, and ONCE Andalusia.